I thought that too before I used them but after several years I've never had noise be an issue, especially with elk.
Im a panhandle of idaho and eastern wa elk hunter....dry brush on my pack is not something that I want to risk.
Two weeks ago I blew a herd at 30 yards in the fog when my pack rubbed a tree and sounded out a warning.
If I were in open country, I wouldn't care...but when you HAVE to hike through dry cover...I'd rather try to sound like animals then velcro.